The statement given in the title is proved. Linear codes over chain rings (commutative and noncommutative) are a natural generalization of linear codes over finite fields and of linear codes over integer residue class rings of prime power order. In matters of linear representability there is no obvious reason why we should prefer one chain ring to the other. Yet, apart from Z4, there is...
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We answer a problem posed by Etzion and Vardy (1998) by showing that a binary code of length N=2(m)-2 with 2(N-m) codewords and minimum distance three can always be lengthened to form a perfect code of length 2(m-1)
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Two distributed systems are considered for discriminating between two finite-alphabet bivariate memoryless sources and for detecting a known signal in stationary bivariate additive Gaussian noise. Each system comprises two sensors, M-ary local quantizers and a fusion center which makes decisions based on quantized source observations. The problem of asymptotically optimal quantization is considere...
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The linear complexity of a de Bruijn sequence is the degree of the shortest linear recursion which generates the sequence. It is well known that the complexity of a binary de Bruijn sequence of length 2n is bounded below by 2n-1+n and above by 2n-1 for n&ges;3. We briefly survey the known knowledge in this area. Some new results are also presented, in particular, ...
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For a given source distribution, we establish properties of the conditional density achieving the rate distortion function lower bound as the distortion parameter varies. In the limit as the distortion tolerated goes to zero, the conditional density achieving the rate distortion function lower bound becomes degenerate in the sense that the channel it defines becomes error-free. As the permitted di...
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We present a cyclotomic approach to the construction of all binary duadic codes of prime lengths. We calculate the number of all binary duadic codes for a given prime length and that of all duadic codes that are not quadratic residue codes. We give necessary and sufficient conditions for p such that all binary duadic codes of length p are quadratic residue (QR) codes. We also show how to determine...
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We give codes on all members after level 4 of the family of Garcia-Stichtenoth (see Invent. Math., vol.121, p.211-22, 1995) curves with the property dtrue>dFR. These codes also give an improvement on Tsfasman-Vladut-Zink bound
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In this article, constructions of generalized concatenated (GC) codes with good rates and distances are presented. Some of the proposed GC codes have simpler trellis complexity than Euclidean geometry (EG), Reed-Muller (RM), or Bose-Chaudhuri-Hocquenghem (BCH) codes of approximately the same rates and minimum distances, and in addition can be decoded with trellis-based multistage decoding up to th...
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A probabilistic analysis is conducted to determine conditional and unconditional correlation weaknesses of cascades of up/down clocked shift registers. Similar results are also obtained for cascades of stop/go clocked shift registers. It is theoretically explained how to use the derived properties for fast correlation attacks, whose objective is to recover the linear feedback shift-register initia...
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We develop deterministic necessary and sufficient conditions on individual noise sequences of a stochastic approximation algorithm for the error of the iterates to converge at a given rate. Specifically, suppose {ρn} is a given positive sequence converging monotonically to zero. Consider a stochastic approximation algorithm x n+1=xn-an(Anx...
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A family of n-dimensional unit norm vectors is an Euclidean superimposed code if the sums of any two distinct at most m-tuples of vectors are separated by a certain minimum Euclidean distance d. Ericson and Gyorfi (1988) proved that the rate of such a code is between (log m)/4m and (log m)/m for m large enough. In this paper-improving the above long-standing best upper bound for the rate-it is sho...
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Entropy-coded vector quantization is studied using high-resolution multidimensional companding over a class of nondifference distortion measures. For distortion measures which are “locally quadratic” a rigorous derivation of the asymptotic distortion and entropy-coded rate of multidimensional companders is given along with conditions for the optimal choice of the compressor function. T...
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We obtain an improved approximation rate (in Sobolev norm) of r -1/2-α(d+1)/ for a large class of single hidden layer feedforward artificial neural networks (ANN) with r hidden units and possibly nonsigmoid activation functions when the target function satisfies certain smoothness conditions. Here, d is the dimension of the domain of the target function, and α∈(0, 1) is...
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Trellis-coded quantizers (TCQ) are designed for the binary erasure channel (BEC) for memoryless sources. When the bit erasure rate is large, the channel-optimized TCQ can provide up to 1.4 dB improvement over TCQ designed for a lossless channel
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We study a combinatorial invariant of codes which counts the number of ordered pairs of codewords in all subcodes of restricted support in a code. This invariant can be expressed as a linear form of the components of the distance distribution of the code with binomial numbers as coefficients. For this reason we call it a binomial moment of the distance distribution. Binomial moments appear in the ...
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In this correspondence, we give a characterization of certain quasi-cyclic self-complementary codes with parameters [120,9,56] and [136,9,64], some quasi-cyclic self-complementary codes are also constructed with parameters [496,11,240] and [528,11,256]. These codes are optimal in the sense that they meet the Grey-Rankin bound, new quasi-symmetric SDP (symmetric difference property) designs are con...
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Symmetrical multilevel diversity coding with independent data streams has been studied by Roche et al. (1992), and the admissible coding rate region was determined for the case of three levels. In particular, it was shown that coding by superposition is optimal, which means that optimality can be achieved by very simple coding. However, it is very difficult to generalize their proof to an arbitrar...
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We give simple sufficient conditions for a code to be rectangular and show that large families of well-known nonlinear codes are rectangular. These include Hadamard (1893), Levenshtein (1964), Delsarte-Goethals (1975), Kerdock (1972), and Nordstrom-Robinson (1967) codes. Being rectangular, each of these codes has a unique minimal trellis that can be used for soft-decision maximum-likelihood decodi...
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A power mapping f(x)=xd over GF(pn) is said to be differentially k-uniform if k is the maximum number of solutions x∈GF(pn) of f(x+a)-f(x)=b where a, b∈GF(pn ) and a≠0. A 2-uniform mapping is called almost perfect nonlinear (APN). We construct several new infinite families of nonbinary APN power mappings
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In 1981 Jahn used the elimination technique of the first author to determine the average errors capacity region of an arbitrarily varying multiple-access channel (AVMAC), when this region has a nonempty interior. Here we remove this restriction. In his thesis (1990), Gubner (1990) missed this result because he used the first author's first approach to the MAC, which is based on conditional decodin...
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Efficient encoding algorithms are presented for two types of constraints on two-dimensional binary arrays. The first constraint considered is that of t-conservative arrays, where each row and each column has at least t transitions of the form `0'→`1' or `1'→`0.' The second constraint is that of two-dimensional DC-free arrays, where in each row and each column the number of `0's equals th...
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The problem of asymptotic (i,e., low-distortion) behavior of the rate-distortion function of a random vector is investigated for a class of non-difference distortion measures. The main result is an asymptotically tight expression which parallels the Shannon lower bound for difference distortion measures. For example, for an input-weighted squared error distortion measure d(x,y)=||W(x)(y-x)||2...
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